Furnace grate-bars



B. P. PERRY; Furnace Grate Bars.

No, 227,124. Patented May 4,4880,

UNITED STATES PATENT OFFICE.

BENJAMIN P. PERRY, OF RICHMOND, INDIANA.

FU RNACE GRATE-BARS.

SPECIFICATION formingpart of Letters Patent No. 227,124, dated May 4, 1880.

Application filed February 24, 1880.

To all whom it may concern:

Be it known that I, BENJAMIN P. PERRY, a citizen of the United States, residing at Richmond, Wayne county, Indiana, have invented new and useful Improvements in Furnace Grate-Bars, of which the following is a specification.

My invention relates to improvements in grate-bars, and is designed to render them more durable and efficient for the purposes for which they are employed.

Heretofore grate-bars have been constructed in corrugated form with a view of exposing a large surface of the iron to the currents of air as a means of protection against the heat of the fire, and also to divide the currents of air ascending between them, and thus attain a more beneficial effect upon the fuel.

This form of grate-bar, however, in practice, is found to be subjectto certain disadvantages, especially when made thin, as necessary. The weight of the superincumbentfuel is very apt, when the bars are heated, to twist them and destroy their proper alignment, and when such occurs they are soon destroyed by the action of the re and impeded air-drafts.

In my improvement I employ a grate-bar with a straight and thin web, and attain the beneficial results of a corrugated bar by suitably disposed and formed projections, as fully hereinafter described, whereby the currents of air ascending to the fuel between the bars are accelerated and their benecial action on the fuel enhanced, while at the same time they impinge upon the iron at every point and eifectually prevent overheating.

These 'and other advantages of my improvements will be more fully set forth in the following specification.

My invention is embodied in a grate-bar shown in the accompanying drawings, in which Figure l is a plan view of a grate composed of a number of my improved bars, showing their relative disposition. Fig. 2 is an end sectional view through the line a' a?. Fig. 3 is a perspective view of a single bar.

Similar letters of reference indicate similar parts in the drawings.

A in the drawings represents my improved grate-bar, which consists of a straight web, a, made thin and wide in the middle to give sufiicient strength to withstand the weight of superimposed fuel, and angular projections b, disposed alternately upon opposite sides.

Inform the projection b approximates a half pyramid or conical prism, as fully shown in the drawings, forming a sort of buttress or bracket resting against the straight web and supporting the fuel. This not only disposes the metal so as to give the greatest strength to bearthe weight upon it, but also forms airchannels, which widen uniformly from the upper edge of the bar downward between adjacent bars.

The object and result of this construction are threefold: first, the vertical air-currents impinge against the iron at every point and keep the latter cool; second, the space between the bars, being least at the upper edge, cannot become clogged with ashes; and, third, the currents of air passing upward between the bars are discharged through a somewhat contracted orifice formed by the upper edges of the bars, and, being expanded by heat strike with greater velocity and force against thefuel.

These advantages result from my peculiar construction of the bar in the particulars before stated, in which it differs from previous constructions, which all exhibit air-passages narrowing at points below the upper surface.

The advantage of the straight web is that greater strength is secured and the liability of warping avoided. In case the bar-should become overheated it sags in a vertical line, and the relative contour of the air-passages is not materially affected. The form of projections b is that which I deem best for the purpose after numerous and careful experiments; but I do not coniine myself strictly thereto, as certain variations may be made without departing from the essential spirit of my invention.

I am aware that gratebars consisting of a central web provided with prismoidal projections are not new 5 butin thesethe projections have been made of uniform thickness from their top surfaces toward the under side of IOO In testimony whereof I have hereunto set 1o my hand in the presence of two subscribing witnesses.

BENJAMIN P. PERRY.

Witnesses:

JOHN C. WHITRIDGE, JOHN L. YARYAN. 

